Abstract The serum-induced kinase (Snk)–spine-associated Rap GTPase-activating protein (SPAR) signaling pathway is reported as a new molecular mechanism in activity-dependent remodeling of synapses. However, the relationship between Snk-SPAR pathway and glutamate-induced excitotoxicity is not well understood. We report here that in cultured hippocampal neurons, glutamate stimulation induces the activation of Snk-SPAR pathway, and leads to a loss of mature dendritic spines. The time-dependent changes in Snk and SPAR expression after glutamate exposure are also elucidated. Furthermore, the activation of Snk-SPAR pathway induced by glutamate treatment can be blocked by an NMDA receptor antagonist, MK801. These results demonstrate that Snk-SPAR pathway may play a pivotal role in glutamate-induced exicitotoxic damage in CNS through regulating the stability of synapse.